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| author | Petr Uzel | 2011-09-15 10:19:17 +0200 |
|---|---|---|
| committer | Karel Zak | 2011-09-27 15:02:44 +0200 |
| commit | 87d83b6ad2e52a3c867fe2f758e4eccaea145a10 (patch) | |
| tree | 8070b155cb22cffecba1338048e18f383e7bbd73 /sys-utils/flock.c | |
| parent | build-sys: add path.h to Makefile.am (diff) | |
| download | kernel-qcow2-util-linux-87d83b6ad2e52a3c867fe2f758e4eccaea145a10.tar.gz kernel-qcow2-util-linux-87d83b6ad2e52a3c867fe2f758e4eccaea145a10.tar.xz kernel-qcow2-util-linux-87d83b6ad2e52a3c867fe2f758e4eccaea145a10.zip | |
flock: make flock(1) work on NFSv4
To pleace an exclusive lock on a file, NFSv4 requires
the file to be opened RW because of the emulation of flock()
by fcntl():
http://www.spinics.net/lists/linux-nfs/msg18502.html
So instead of O_RDONLY, open the file in O_RDWR if access()
indicates it is possible (unless shared lock is requested).
From: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
Diffstat (limited to 'sys-utils/flock.c')
| -rw-r--r-- | sys-utils/flock.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/sys-utils/flock.c b/sys-utils/flock.c index 7d321de0d..a5003193e 100644 --- a/sys-utils/flock.c +++ b/sys-utils/flock.c @@ -129,6 +129,7 @@ int main(int argc, char *argv[]) int have_timeout = 0; int type = LOCK_EX; int block = 0; + int open_accmode; int fd = -1; int opt, ix; int do_close = 0; @@ -211,9 +212,11 @@ int main(int argc, char *argv[]) } filename = argv[optind]; - fd = open(filename, O_RDONLY|O_NOCTTY|O_CREAT, 0666); + open_accmode = ((type == LOCK_SH || access(filename, R_OK|W_OK) < 0) ? + O_RDONLY : O_RDWR); + fd = open(filename, open_accmode|O_NOCTTY|O_CREAT, 0666); /* Linux doesn't like O_CREAT on a directory, even though it should be a - no-op */ + no-op; POSIX doesn't allow O_RDWR or O_WRONLY */ if (fd < 0 && errno == EISDIR) fd = open(filename, O_RDONLY|O_NOCTTY); |